Visualized: Sony teases prototype 4K cameras and lenses at NAB

At its NAB 2013 press conference, Sony told us several times that it never stops thinking about the future. It's fitting, then, that in addition to announcing pricing for two 4K sets, the company gave us a taste of what's to come a few years down the line. A wide variety of lenses, including both current models and some prototypes, appeared on stage briefly -- behind ropes, no less -- and while we got no shortage of shots, specs, model names and any other particulars were strictly off-limits. Cu...